Nearly a billion people use mobile phones in India and all the mobile masts consumes a lot of energy.
Towers that are located in urban areas are usually connected to the main grid to get electricity.
But most locations in India do not get a continuous or even good quality grid supply, and more than 60% of the towers depend on diesel-powered generators.
Each mast requires about the same amount of energy as the average urban household.
400,000 across the country - and many more planned - the total is huge, and it is perhaps no surprise that India is asking if they can switch to cleaner energy.
The telecom industry one of India's largest consumers of diesel fuel at nearly two billion litres every year, which is both expensive and polluting.
The local telecom regulator has recommended that companies reduce their dependency on diesel and cut carbon emissions by 50% at all rural towers and 20% at urban towers.
Their solution is to run these towers on hybrid power, a combination of renewable and grid power.
solar is the most efficient source currently, but even that does not come cheap.
The company has begun the shift to sustainable sources of energy at more than 1,000 tower sites. This has led to savings of nearly seven million litres of diesel a year.
The paradigm is of having very large power plants and inefficient transmission networks,
The biggest challenge remains the commercial viability of green power.
In an attempt to further develop the market, the country is expected to add another 300,000 towers over the next five years.
Unless an effective clean energy model is developed soon, many fear that fuel costs will bleed an industry that is already heavily in debt.
watch this space